Thermoplastic composition for use in  high impact applications

ABSTRACT

A thermoplastic composition comprising from about 50 to about 99 by weight percent of a nylon 6,6 resin, from about 1 to about 50 by weight percent of a polymer performance modifier and about from 0.01 to about 25 by weight percent of a silicone based additive, wherein the silicone based additive comprises an ultrahigh molecular weight siloxane polymer that is unfunctionalized and non-reactive with the polyamide resin, wherein the thermoplastic composition has an impact strength value which is greater than the combination of the polyamide resin and the polymer performance modifier or the combination of the polyamide resin and the silicone based additive and wherein the thermoplastic composition has an ultimate tensile strength that is at least 80% that of the combination of the polyamide resin and the polymer performance modifier.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority filing dates of U.S. ProvisionalApplication Ser. No. 61/675,990, filed Jul. 26, 2012, and U.S.Provisional Application Ser. No. 61/737,481, filed Dec. 14, 2012, thedisclosures of which are specifically incorporated herein by referencein their entireties.

FIELD OF THE INVENTION

This disclosure relates to polyamide compositions with improved impactstrength.

BACKGROUND OF THE INVENTION

Nylon polymers are desirable in many applications due to its theiroutstanding elasticity, dye-fastness and high melting point. Nylonpolymers commonly take the form of pellets or flakes, which can bemelted and shaped for use in plastic applications; or extruded as fiberfor use in yarn applications, such as apparel, carpet, airbags andoutdoor gear.

In recent years, nylon resins have been utilized for automotive,electronics, industrial and consumer applications. In order to meet theperformance standards for these applications, Nylon resins are commonlyenhanced with additives such as impact modifiers and mineral orsynthetic reinforcements.

Impact modified nylon compositions are useful for industrialapplications because they generally possess good impact strength,stiffness and weld line strength. U.S. Pat. Nos. 4,346,194 and6,579,581, teach nylon resins with impact modifying components. Commonimpact modifiers are elastomeric, olefinic copolymers grafted withcarboxyl or carboxylate functional groups. It is desirable to have nyloncompositions with a high impact strength and stiffness. However, it iswell known and understood that improving the impact strength of apolymer composition with commercially available modifiers generallyresults in a proportional decrease in tensile strength. Due to thisinverse relationship, to achieve a significant increase in impactstrength for a composition, a corresponding decrease in tensile strengthmust also be expected. This inverse relationship limited the use ofimpact modified nylon compositions when tensile strength requirementscannot be met.

Therefore, there is a need for thermoplastic molding compositions thatpossess increased impact strength and similar tensile strength to thebase resin used in the composition.

SUMMARY OF THE INVENTION

The present invention relates to a thermoplastic composition thatcomprises a polyamide resin, a polymer performance modifier and asilicone based additive. The resulting thermoplastic composition has animpact strength that is greater than the combination of the polyamideresin and polymer performance modifier alone and a tensile strength thatis comparable the polyamide resin.

In one embodiment of the present invention the thermoplastic compositioncomprises from about 25 to about 99 by weight percent of a polyamideresin; from about 1 to about 50 by weight percent of a polymerperformance modifier; and about from 0.01 to about 25 by weight percentof a silicone based additive.

In another embodiment, the thermoplastic composition has an impactstrength value which is greater than the combination of the polyamideresin and the polymer performance modifier or the combination of thepolyamide resin and the silicone based additive. The silicone basedadditive comprises an ultrahigh molecular weight siloxane polymer whichmay be unfunctionalized and non-reactive with the polyamide resin. Foruniform performance, it may be desirable to evenly distribute thesilicone based additive throughout the thermoplastic composition.

In another embodiment, the thermoplastic composition has an ultimatetensile strength that is at least 80% that of the combination of thepolyamide resin and the polymer performance modifier.

The polymer performance modifier comprises an elastomeric polyolefinicpolymer functionalized with an unsaturated carboxylic acid anhydride.

In another embodiment, the polymer performance modifier comprises amaleic anhydride functionalized elastomeric ethylene copolymer, a maleicanhydride functionalized ethylene, α-olefin copolymer, a terpolymer ofethylene, acrylic ester and maleic anhydride, a maleic anhydride grafted(MAH) polyolefin elastomer and combinations thereof

Thermoplastic compositions which are the subject of this discovery mayfurther comprise additives such as lubricants, glass fillers, mineralfillers, plasticizers, pigments, dyes, antioxidants, heat stabilizers,hydrolysis stabilizers, nucleating agents, flame retardants, blowingagents and combinations thereof.

The mineral fillers include but are not limited to kaolin, clay, talc,and wollastonite, diatominte, titanium dioxide, mica, amorphous silicaand combinations thereof.

Similarly, the glass fillers are selected from the group consisting ofshort glass fiber, long glass fiber, continuous glass fiber, glassflakes, glass beads and combinations thereof.

The glass fillers may be hydrolysis resistant glass fibers coated with asizing composition and organosilane coupling agents depending on theapplication.

Heat stabilizers are selected from the group consisting of hinderedphenols, amine antioxidants, hindered amine light stabilizers (HALS),aryl amines, phosphorus based antioxidants, copper heat stabilizers,polyhydric alcohols, tripentaerythritol, dipentaerythritol,pentaerythritol and combinations thereof.

The polyamide resin may be any polyamide for which impact resistance isdesired, including Nylon 6, Nylon 6,6, Nylon 6,12, Nylon 4,6, Nylon6,10, Nylon 7, Nylon 10, Nylon 10, 10, Nylon 12, Nylon 12, 12, Nylon 6T,Nylon 6I, Nylon DT, Nylon DI, Nylon 6T/6I, Nylon 6T/DT, Nylon 6/6,6,Nylon DT/DI, Nylon MXD-6 and blends and copolymers thereof.

In another embodiment, the thermoplastic composition further comprisesfrom about 0.1 to about 5.0 by weight of an olefin and maleic anhydridecopolymer, wherein the an olefin and maleic anhydride copolymer has amolecular weight in the range of about 300 to about 1,000,000 and theratio of olefin to maleic anhydride is 1:1. In this embodiment, wherethe olefin is ethylene, it is possible to produce a shear viscositygreater than 1000 Pa when tested at a shear rate of 100 sec-1.Additionally, it is possible to produce a thermoplastic composition witha shear viscosity that is greater than 2000 Pa when tested at a shearrate of 30 sec-1.

In another embodiment, the polymer performance modifier is present in anamount from about 16% to about 18% by weight and the silicone basedadditive is present in an amount from about 1.0% to about 5.0% byweight. Notably, when the polymer performance modifier is present inabout 16% by weight and the silicone based additive is present in anamount from about 1.0% to about 5.0% by weight, it is possible torealize an impact strength of at least 70 kJ/m2 when tested at roomtemperature.

In another embodiment, the polymer performance modifier is present in anamount from about 18% to about 22% by weight and the silicone basedadditive is present in an amount from about 1.0% to about 5.0% byweight, wherein the impact strength is at least 80 kJ/m2 when tested atroom temperature.

In another embodiment, the invention provides favorable tensile strengthwhen polymer performance modifier is present at about 16% to about 22%by weight and the silicone based additive is present in an amount fromabout 1.0% to about 5.0% by weight. It has been found that the tensilestrength is at least 20 Mpa at 50% elongation When tested at 100%moisture saturation. Additionally, no break was observed at 200%elongation when tested at 100% moisture saturation.

The thermoplastic compositions may be formed into molded articles usefulin fields requiring impact resistance and strength, such as automotiveparts. Additional applications include blow molded or injection moldedapplications, pneumatic duct work, pipes, tubing, chemical containers,gas tanks, fasteners and snap fit parts, hinged parts, gears andbearings, sporting goods, ski bearings, sprinkler heads, drivingbarrels, microcellular foam processing, lawn mower parts or appliances.

Also provided is a process for forming the thermoplastic compositioncomprising the steps of adding a polymer performance modifier and asilicone based additive to a polyamide resin and then mixing the polymermodifier, silicone based additive and polyamide resin together to form ahigh impact polymer.

Further provided is a process for increasing the impact strength in apolymer comprising the steps of: adding a polymer performance modifierand a silicone based additive comprising an ultrahigh molecular weightsiloxane polymer to a polyamide resin and mixing the polymer modifier,silicone based additive and polyamide resin to form a high impactpolymer, which exhibits an ultimate tensile strength of at least 80%that of the tensile strength of the combination of the polyamide resinwith the polymer modifier. The polymer performance modifier of thisprocess comprises an impact modifier that may be selected from a groupconsisting of a maleic anhydride functionalized elastomeric ethylenecopolymer, a maleic anhydride functionalized ethylene, α-olefincopolymer, a terpolymer of ethylene, acrylic ester and maleic anhydride,a maleic anhydride grafted (MAH) polyolefin elastomer and combinationsthereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a chart summarizing the impact strength of unreinforced nylon6,6 resin with various amounts of a polymer performance modifier and asilicone based additive.

FIG. 2 is a chart summarizing the impact strength of unreinforced nylon6,6 resin with various amounts of a polymer performance modifier and asilicone based additive tested at −40° C.

FIG. 3 is a chart summarizing the impact strength of unreinforced nylon6,6 resin with various amounts of a polymer performance modifier and asilicone based additive tested at room temperature.

FIG. 4 is a chart summarizing the tensile strength of unreinforced nylon6,6 resin with various amounts of a polymer performance modifier and asilicone based additive tested after moisture conditioning.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a thermoplastic composition thatcomprises a polyamide resin, a polymer performance modifier and asilicone based additive. The resulting thermoplastic composition has animpact strength that is greater than the combination of the polyamideresin and polymer performance modifier alone and a tensile strength thatis comparable the polyamide resin.

In an exemplary embodiment of the current invention, the thermoplasticcomposition comprises from about 25 to about 99 by weight percent of apolyamide resin; from about 1 to about 50 by weight percent of a polymerperformance modifier; and about from 0.01 to about 25 by weight percentof a silicone based additive. Due to the high impact strength and lowflexibility of the thermoplastic composition, molded articles comprisingthe thermoplastic composition are useful for many industrialapplications. One preferred use is to create thermoplastic articlesbeneficial to the automotive industry.

Other uses of the current thermoplastic composition include, but are notlimited to blow molded or injection molded applications, pneumatic ductwork, pipes, tubing, chemical containers, gas tanks, fasteners and snapfit parts, hinged parts, gears and bearings, sporting goods, skibearings, sprinkler heads, driving barrels, microcellular foamprocessing (i.e. Mucell® Technology), lawn mower parts or appliances.

In an exemplary embodiment of the current invention, the silicone basedadditive comprises an ultrahigh molecular weight siloxane polymer andmay further comprise a binding agent. The ultrahigh molecular weightsiloxane polymer is unfunctionalized and non-reactive with the polyamideresin. In addition, an unfunctionalized siloxane polymer cannot beconsidered as either a gel or an oil. Suitable binding agents for thesilicone based additive include fumed silica. The silicone basedadditive may be provided in a pelletized silicone gum formulation. Acommercially available formulation is sold under the name Genioplast®Pellet S by Wacker.

This thermoplastic composition exhibits the unexpected and remarkablefinding that the impact performance of a thermoplastic compositioncontaining a polyamide resin is greatly improved by the synergisticcombination of a performance modifier and an ultrahigh molecular weightsiloxane polymer. The thermoplastic composition of the present inventionhas been shown to undergo uniform deformation upon stress and loading.In addition, the thermoplastic composition of the present invention hasimproved impact resistance, toughness, low temperature ductility,fatigue resistance, wear resistance, resistance to necking, and elasticrecovery. The thermoplastic composition of the present invention alsoprovides high burst pressure and an improved surface appearance forglass filled resins.

This unforeseen behavior of siloxane polymer is believed to be due toits immobility in the continuous phase of the nylon composition, whichallows it to evenly distribute throughout the thermoplastic composition.The high molecular weight nature prevents the siloxane polymer frommigrating or diffusing to the surface, and eventually dissipating, thathelps in dampening the impact energy in conjunction with the performancemodifier. Gels or Oils, on the other hand, would tend to migrate to thesurface because of very high diffusivity, especially at processingconditions. It has also been found that the silicone from thetraditional silicone based additive blooms to the surface of thethermoplastic composition creating a non-uniform dispersion if thecomposition components.

It may be further desirable to increase the melt viscosity of thethermoplastic composition. In this fashion, a thermoplastic compositionis provided comprising from about 50 to about 99 by weight percent of apolyamide resin; from about 1 to about 50 by weight percent of a polymerperformance modifier; from 0.01 to about 25 by weight percent of asilicone based additive; and from about 0.1 to about 5.0 by weight of anolefin and maleic anhydride copolymer, wherein the an olefin and maleicanhydride copolymer has a molecular weight in the range of about 300 toabout 1,000,000 and the ratio of olefin to maleic anhydride is 1:1.Suitable olefins include any such that are known in the art. In oneexemplary embodiment of the current invention, the olefin is ethylene. Acommercially available 1:1 copolymer of ethylene and maleic anhydride issold under the name ZeMac® by Vertellus®. As described in Example 4, theshear viscosity can be increased to a range of about 1000 to about 2100Pa when tested at a shear rate range from about 30 to about 100 sec⁻¹.At this melt viscosity, the thermoplastic composition can be used forblow molding and pipe extrusion applications.

Suitable polyamide resins that may be used for the current inventioninclude any known polyamides in the art. These include, but are notlimited to: aliphatic, semicrystalline, aromatic or semiaromatic nylonresins. The nylon resins are those prepared from starting materials ofessentially a lactam or a diamine, and an aliphatic, semiaromatic oraromatic dicarboxylic acid. Suitable lactams include caprolactam andlaurolactam. Suitable amines include tetramethylenediamine,hexamethylenediamine (HMD), 2-methylpentamethylenediamine,undecamethylenediamine, dodecamethylenediamine,2,2,4-/2,4,4-trimethylhexamethylenediamine,5-methylnonamethylenediamine, metaxylylenediamine (MXD),paraxylylenediamine and 2-Methyl-1,5-pentamethylenediamine (MPMD).Suitable dicarboxylic acids include those such as: adipic acid, subericacid, azelaic acid, sebacic acid, dodecanedioic acid (DDDA),terephthalic acid (TPA), isophthalic acid (IPA), 2-chloroterephthalicacid, 2-methylterephthalic acid, 5-methylisophthalic acid,5-sodium-sulfoisophthalic acid, hexahydroterephthalic acid andhexahydroisophthalic acid. In the invention, nylon homopolymers orcopolymers to be derived from those starting materials are used eithersingly or as their mixtures.

Specific examples of polyamide resins that are desirable forthermoplastic compositions of the subject disclosure, are: (nylon 6),polyundecanamide (nylon 11), polylauramide (nylon 12),polyhexamethylenadipamide (nylon 66), polytetramethylenadipamide (nylon46), polyhexamethylenesebacamide (nylon 610),polyhexamethylenedodecamide (nylon 612),polyhexamethyleneterephthalamide (6T), polyhexamethylenisophthalamide(6I), 2-methylpentamethylene terephthalamide (DT),2-methylpentamethylene isophthalamide (DI),polyhexamethyleneterephthalamide/polycapramide copolymer (nylon 6T/6),polyhexamethyleneterephthalamide/polydodecanamide copolymer (nylon6T/12), polyhexamethylenadipamide/polyhexamethyleneterephthalamidecopolymer (nylon 66/6T),polyhexamethylenadipamide/polyhexamethylenisophthalamide copolymer(nylon 66/6I),polyhexamethylenadipamide/polyhexamethylenisophthalamide/-polycapramidecopolymer (nylon 66/6I/6),polyhexamethylenadipamide/polyhexamethyleneterephthalamide/polyhexamethylenisophthalamidecopolymer (nylon 66/6T/6I),polyhexamethyleneterephthalamide/-polyhexamethylenisophtha lamidecopolymer (nylon 6T/6I),polyhexamethyleneterephthalamide/poly(2-methylpentamethylene)terephthalamidecopolymer (nylon 6T/M5T),polyhexamethyleneterephthalamide/-polyhexamethylenesebacamide/polycapramidecopolymer (nylon 6T/610/6),polyhexamethyleneterephthalamide/polydodecanamide/-polyhexamethylenadipamidecopolymer (nylon 6T/12/66),polyhexamethyleneterephthalamide/polydodecanamide/-polyhexamethylenisophthalamidecopolymer (nylon 6T/12/6I), poly m-xylylenadipamide (nylon MXD6), aswell as their mixtures and copolymers, etc.

Especially preferred are nylon resins suitable for the current inventionare Nylon 6, Nylon 6,6, Nylon 6,12, Nylon 4,6, Nylon 6,10, Nylon 7,Nylon 10, Nylon 10, 10, Nylon 12, Nylon 12, 12, Nylon 6T, Nylon 6I,Nylon DT, Nylon DI, Nylon MXD-6 and combinations or copolymers thereof.In another exemplary embodiment of the current invention the polyamideresin is Nylon 6,6.

The thermoplastic compositions taught herewith each exhibit an strengthvalue which is greater than the combination of the polyamide resin andthe polymer performance modifier or the combination of the polyamideresin and the silicone based additive. In addition, the thermoplasticcomposition has an ultimate tensile strength that is at least 80% thatof the combination of the polyamide resin and the polymer performancemodifier.

Suitable polymer performance modifiers include those known in the artthat impart improved impact strength when combined with polyamideresins. U.S. Pat. Nos. 4,346,194, 6,579,581 and 7,671,127, hereinincorporated by reference, teach nylon resins with impact modifyingcomponents. In an exemplary embodiment of the current invention thepolymer modifier comprises an elastomeric polyolefinic polymerfunctionalized with an unsaturated carboxylic acid anhydride.

Suitable elastomers are polymers or copolymers of ethylene and otherα-olefins or copolymers of α-olefins with alkyl acrylate, acrylic esteror alkyl methacrylate. Other suitable elastomers includestyrene-butadiene di-block copolymers (SB), styrene-butadiene-styrenetri-block copolymers (SBS), styrene-isoprene-styrene tri-blockcopolymers (SIS) and hydrogenated styrene-ethene/butene-styrenetri-block copolymers (SEBS). Other elastomers that may be used includeterpolymers of ethylene, propylene, and diene monomers (EPDM rubber). Asused herein, the term “α-olefins” or alpha-olefins refer to olefins oralkenes with a chemical formula C_(x)H_(2x), wherein they have a doublebond at the primary or alpha (α) position.

Suitable functional groups include carboxylic acid groups, carboxylicanhydride groups, carboxylic ester groups, carboxamide groups,carboximide groups, amino groups, hydroxy groups, epoxy groups, urethanegroups, and oxazoline groups. Examples of suitable monomers forintroducing the functional groups are maleic anhydride, itaconic acid,acrylic acid, glycidyl acrylate, and glycidyl methacrylate.

Suitable polymer performance modifiers are commercially available, suchas that sold by Dow® under the name Amplify™ GR216 which is a maleicanhydride functionalized polyolefin elastomer. Another suitablecommercially available polymer performance modifier is sold by Arkema®under the name Lotader® 4700 and is a random terpolymer of ethylene,ethyl acrylate and maleic anhydride. Yet another suitable commerciallyavailable polymer performance modifier is sold by ExxonMobil® under thename Exxelor™ VA 1840 and is a semi-crystalline ethylene copolymerfunctionalized with maleic anhydride. Yet further, another suitablecommercially available performance modifier is sold by Arkema® under thename Orevac® IM300 and is a maleic anhydride modified low-densitypolyethylene. Other polymer performance modifiers are commonly used.

The thermoplastic composition of the current invention may furthercomprise additives such as lubricants, glass fillers, mineral fillers,plasticizers, pigments, dyes, antioxidants, heat stabilizers, hydrolysisstabilizers, nucleating agents, flame retardants, blowing agents andcombinations thereof. Suitable mineral fillers can be selected from thegroup consisting of kaolin, clay, talc, and wollastonite, diatominte,titanium dioxide, mica, amorphous silica and combinations thereof.Suitable glass fillers are selected from the group consisting of shortglass fiber, long glass fiber, continuous glass fiber, glass flakes,glass beads and combinations thereof. As used herein, short glass fiberrefer to chopped glass fibers and glass fiber that is 3.175 mm orshorter in length. Long glass fibers have a length greater than 3.175 mmin length. As used herein, continuous glass fiber refer to glassrovings. The glass fibers may also be coated with a sizing compositionand organosilane coupling agents to provide hydrolysis resistance.Suitable coated glass fibers are taught in U.S. Pat. Nos. 6,207,737,6,846,855, 7,419,721 and 7,732,047, which are herein incorporated byreference. Suitable heat stabilizers are selected from the groupconsisting of hindered phenols, amine antioxidants, hindered amine lightstabilizers (HALS), aryl amines, phosphorus based antioxidants, copperheat stabilizers, polyhydric alcohols, tripentaerythritol,dipentaerythritol, pentaerythritol and combinations thereof.

In one exemplary embodiment, the thermoplastic composition of thecurrent invention is formed by adding a polymer performance modifier anda silicone based additive comprising an ultrahigh molecular weightsiloxane polymer additive to a polyamide resin and mixing the polymerperformance modifier, silicone based additive and polyamide resin toform a high impact polymer. The high impact polymer has an ultimatetensile strength that is at least 80% that of the combination of thepolyamide resin and polymer performance modifier. Suitable equipment forblending the polyamide resin, siloxane polymer and performance modifierinclude a twin-screw extruder, melt kneader or batch mixer. Thethermoplastic composition is suitable for compounding or for use as amasterbatch.

In preferred embodiments the polymer performance modifier comprises amaleic anhydride functionalized elastomeric ethylene copolymer, a maleicanhydride functionalized ethylene, α-olefin copolymer, a terpolymer ofethylene, acrylic ester and maleic anhydride, a maleic anhydride grafted(MAH) polyolefin elastomer or combinations thereof. In a preferredembodiment of this process, the polyamide resin is Nylon 6,6.

All patents, patent applications, test procedures, priority documents,articles, publications, manuals, and other documents cited herein arefully incorporated by reference to the extent such disclosure is notinconsistent with this invention and for all jurisdictions in which suchincorporation is permitted.

EXAMPLES

The following Examples demonstrate the present invention and itscapability for use. The invention is capable of other and differentembodiments, and its several details are capable of modifications invarious apparent respects, without departing from the scope and spiritof the present invention. Accordingly, the Examples are to be regardedas illustrative in nature and non-limiting.

Comparative Example 1

TABLE 1 Control Nylon 66 (Average Values) Tensile Strength @ yield, Mpa47-50 Strain @ yield, % 4.4 Strain @ break, % 34.2 Ten Mod, Mpa1940-2000 R.T. Notched Charpy. kJ/m2 76

Table 1 shows the strength characteristics for INVISTA formulation nylonresin that contains 42-65% by weight of nylon 6,6 composition having acopper iodide heat stabilizer and an aluminum stearate lubricant. Theresin also contains 22% of a polymer performance modifier of ethylenecopolymer functionalized with maleic anhydride (i.e.: Exxelor™ VA1840)and no silicon based additive.

Example 1

TABLE 2 1 2 3 4 5 6 7 8 9 10 11 12 A B C D E F G H J K L M Nylon 6681.47 79.47 77.47 79.47 77.47 75.47 77.47 75.47 73.47 75.47 73.47 71.47Exxelor VA1840 16 16 16 18 18 18 20 20 20 22 22 22 Shepherd 8:1:1 HS

0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 CNH-00509 11 1 1 1 1 1 1 1 1 1 1 UHMW S

1 3 5 1 3 5 1 3 5 1 3 5 Al Stearate 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.20.2 0.2 0.2 Tota

100 100 100 100 100 100 100 100 100 100 100 100 Notched Charpy, 48.472.3 79.2 68.1 83.2 98.8 80.7 90.7 96.4 90.3 98.6 103.1 kJ/m2 at R.T.Notched Charpy, 14.4 17.3 19.6 14.9 20.6 19.65 19.1 23.06 44.7 20.7 26.669.7 kJ/m2 at −40

TS @ yield, Mpa 56.7 53 50.4 53.3 50 47.7 50.5 47.7 45.5 48.3 45.2 43.4Strain @ yield, % 5.4 5.5 5.9 6.4 6.2 5.8 6.6 6.7 9.4 6.8 10 29 Strain @break, % 21.6 35.7 35.4 26.2 38.6 42.6 31 36.3 50.3 32.7 42 61 Ten Mod,Mpa 2117 2320 1990 2046 2005 1918 2255 1934 1941 1995 1827 2389

indicates data missing or illegible when filed

Table 2 summarizes the results from adding various amounts of a siliconebased additive and polymer performance polymer additive to INVISTAformulation unreinforced nylon 6,6 resin. The silicone based additiveadded was pelletized silicone gum formulation sold under the nameGenioplast® Pellet S by Wacker. The pellets contain about 65% by weightof ultra high molecular weight siloxane gum content. The polymerperformance polymer additive was an ethylene copolymer functionalizedwith maleic anhydride sold by ExxonMobil® under the name Exxelor™ VA1840. The results show that high level tough impact properties areachieved without sacrificing other properties such as flexuralproperties, tensile strength, modulus surface finish and tribology. Forexample, at room temperature (R.T.) and at 16% impact modifier and 5%siloxane gum loading an impact strength of 79.2 Kj/m2 and tensilestrength of 50.5 Mpa was achieved. This is a significant increase fromthe impact strength from the comparative example at the same polymerperformance modifier level (16.8 Kj/m2). In fact, the impact strengthstill remains higher than when the comparative example has an polymerperformance modifier level of 22% (76.4 Kj/m2). FIG. 1 summarizes thecomparison of the impact strength of the unreinforced INVISTAformulation nylon 6,6 resin at various loadings of Genioplast® Pellet Sand Exxelor™ VA 1840 (tested at R.T.). As shown in FIG. 1, when thepolymer performance modifier is present at about 16% by weight and thesilicone based additive is present in an amount from about 1.0% to about5.0% by weight, the impact strength is at least about 70 kJ/m2 whentested at room temperature. In addition, when the polymer performancemodifier is present in an amount from about 18% to about 22% by weightand the silicone based additive is present in an amount from about 1.0%to about 5.0% by weight, the impact strength is at least about 80 kJ/m2when tested at room temperature. In addition, the tensile strength ofthe sample remained substantially the same. It was shown that thetensile strength of the samples at various siloxane gum remained within80% of that of the resin from the comparative example.

Example 2

FIG. 2 and FIG. 3 show samples of INVISTA formulation unreinforced nylon6,6 resin that are combined with various amounts of silicone basedadditive and a polymer performance modifier. FIG. 2 shows the results at−40° C. and FIG. 3 shows the results at room temperature (R.T.). Thesilicone based additives were Genioplast® pellets. The polymerperformance modifier was a maleic anhydride polyolefin elastomer sold byDow® under the name Amplify™ GR 216. FIGS. 2 and 3 both show that asignificant increase in impact strength greater can be achieved usingthe combination of the polymer performance modifier and siloxane gumadditive. As shown in FIG. 2, when the polymer performance modifier ispresent in an amount from about 16% to about 22% by weight and thesilicone based additive is present in an amount from about 1.0% to about5.0% by weight, the impact strength is at least about 20 kJ/m2 whentested at −40° C.

Example 3

FIG. 4 shows samples of INVISTA formulation unreinforced nylon 6,6 resinthat are combined with various amounts of silicone based additive and apolymer performance modifier. The silicone based additives wereGenioplast® pellets. The polymer performance polymer additive was anethylene copolymer functionalized with maleic anhydride sold byExxonMobil® under the name Exxelor™ VA 1840. The specimens wereconditioned in saturated moisture at 80° C. for 17 days in a closedcontainer to achieve 100% saturation. The results are summarized inTable 3. As can be seen the tensile strength of the samples with 22%polymer performance modifier (21.9-23.7 Mpa) is well within 80% of thetensile strength of the sample with no silicone based additive (24.4Mpa). FIG. 4 shows the tensile strength of the samples when tested at50% elongation. In addition, no break was observed in the samples whentested at 200% elongation.

TABLE 3 Wt of specimen % MOI absorbed after conditioning in Wt of DAM @80 C. TS @ Sample % Exxelor % IMD closed box at 80 specimen, for 17 daysyield, % Strain RB-041 VA 1840 additive deg C./17 day (gms) gms (100%RH) Mpa @ yield % Strain @ break A 16 1 10.3214 9.8046 5.28 27.2 50 nobreak @ 200% B 16 3 10.4348 9.832 6.14 25.7 50 no break @ 200% C 16 510.3537 9.7574 6.12 25.4 50 no break @ 200% D 18 1 10.2841 9.6958 6.0725.3 50 no break @ 200% E 18 3 10.1927 9.6935 5.15 24.9 50 no break @200% F 18 5 10.2734 9.6823 6.11 23.6 50 no break @ 200% G 20 1 10.14599.6285 5.38 24.9 50 no break @ 200% H 20 3 10.1685 9.6507 5.37 24.1 50no break @ 200% J 20 5 10.1585 9.6374 5.41 23.6 50 no break @ 200% K 221 10.188 9.6219 5.89 23.7 50 no break @ 200% L 22 3 10.0919 9.5358 5.8422.7 50 no break @ 200% M 22 5 10.067 9.5174 5.78 21.9 50 no break @200% F11-0111 22 0 10.0517 9.4942 5.88 24.4 50 no break @ 200% ACS Lot

Example 4

Example 4 exhibits how the melt viscosity of the thermoplasticcomposition can be increased with the addition of a copolymer ofethylene and maleic anhydride. Table 4 compares the melt viscosity,which is tested by measuring the shear viscosity, of various resins.Sample 1 is an INVISTA formulation unreinforced nylon 6,6 resin that iscombined with a silicone based additive and a polymer performancemodifier. Sample 2 is an INVISTA formulation unreinforced nylon 6,6resin that is combined with a silicone based additive, a polymerperformance modifier and a 1:1 copolymer of ethylene and maleicanhydride. The silicone based additives were Genioplast® pellets. Thepolymer performance polymer additive was an ethylene copolymerfunctionalized with maleic anhydride sold by ExxonMobil® under the nameExxelor™ VA 1840. The 1:1 copolymer of ethylene and maleic anhydride issold by Vertellus® under the name ZeMac®. Sample 3 is a comparativeexample showing the melt viscosity of a high density polyethylene (HDPE)resin. The shear viscosity was measured using a capillary rheometer atvarious shear rates. As shown in Table 4 below, the shear viscosity (andcorrespondingly the Melt Viscosity) of Sample 2 showed a significantincrease over Sample 1 at lower shear rates.

TABLE 4 Sample 1 Sample 2 Sample 3 B G HDPE (180 C.) Nylon 6,6 70 69Exxelor VA 1840 22 22 ZeMac 60 1 Wacker Pellet S 5 5 Cu based Heat 0.30.3 Stabilizer phenolic antioxidants 0.5 0.5 Carbon Black 2 2 ZnStearate 0.2 0.2 Total 100 100 Shear Rate (sec −1) Shear Viscosity (Pa)10040.2 30.5 43.5 35.1 5020.1 47.3 73.0 60.7 4016.0 53.1 85.7 69.73011.0 63.8 104.1 90.5 2006.6 79.7 136.8 121.9 1001.8 113.3 221.0 180.8499.7 159.4 362.5 310.7 296.3 200.3 525.3 454.2 148.2 273.2 827.5 807.7100.0 325.5 1052.3 1180.1 50.0 461.0 1480.5 1900.3 30.0 584.2 2062.82597.4

It should be noted that ratios, concentrations, amounts, and othernumerical data may be expressed herein in a range format. It is to beunderstood that such a range format is used for convenience and brevity,and thus, should be interpreted in a flexible manner to include not onlythe numerical values explicitly recited as the limits of the range, butalso to include all the individual numerical values or sub-rangesencompassed within that range as if each numerical value and sub-rangeis explicitly recited. To illustrate, a concentration range of “about0.1% to about 5%” should be interpreted to include not only theexplicitly recited concentration of about 0.1 wt % to about 5 wt %, butalso the individual concentrations (e.g., 1%, 2%, 3%, and 4%) and thesub-ranges (e.g., 0.5%, 1.1%, 2.2%, 3.3%, and 4.4%) within the indicatedrange. The term “about” can include ±1%, ±2%, ±3%, ±4%, ±5%, ±8%, or±10%, of the numerical value(s) being modified. In addition, the phrase“about ‘x’ to ‘y’” includes “about ‘x’ to about ‘y’”.

While the illustrative embodiments of the invention have been describedwith particularity, it will be understood that the invention is capableof other and different embodiments and that various other modificationswill be apparent to and may be readily made by those skilled in the artwithout departing from the spirit and scope of the invention.Accordingly, it is not intended that the scope of the claims hereof belimited to the examples and descriptions set forth herein but ratherthat the claims be construed as encompassing all the features ofpatentable novelty which reside in the present disclosure, including allfeatures which would be treated as equivalents thereof by those skilledin the art to which the invention pertains.

What is claimed:
 1. A thermoplastic composition comprising from about 50to about 99 by weight percent of a polyamide resin; from about 1 toabout 50 by weight percent of a polymer performance modifier; and aboutfrom 0.01 to about 25 by weight percent of a silicone based additive. 2.The thermoplastic composition of claim 1 wherein the thermoplasticcomposition has an impact strength value which is greater than thecombination of the polyamide resin and the polymer performance modifieror the combination of the polyamide resin and the silicone basedadditive.
 3. The thermoplastic composition of claim 1 wherein thethermoplastic composition has an ultimate tensile strength that is atleast 80% that of the combination of the polyamide resin and the polymerperformance modifier.
 4. The thermoplastic composition of claim 1wherein the silicone based additive comprises an ultrahigh molecularweight siloxane polymer.
 5. The thermoplastic composition of claim 4wherein the ultrahigh molecular weight siloxane polymer isunfunctionalized and non-reactive with the polyamide resin.
 6. Thethermoplastic composition of claim 1 wherein the polymer performancemodifier comprises an impact modifier.
 7. The thermoplastic compositionof claim 6 wherein the impact modifier is an elastomeric polyolefinicpolymer functionalized with an unsaturated carboxylic acid anhydride. 8.The thermoplastic composition of claim 6 wherein the impact modifier isselected from a group consisting of a maleic anhydride functionalizedelastomeric ethylene copolymer, a maleic anhydride functionalizedethylene, α-olefin copolymer, a terpolymer of ethylene, acrylic esterand maleic anhydride, a maleic anhydride grafted (MAH) polyolefinelastomer and combinations thereof
 9. The thermoplastic composition ofclaim 1 further comprising a heat stabilizer.
 10. The thermoplasticcomposition of claim 9 wherein the heat stabilizer is selected from thegroup consisting of hindered phenols, amine antioxidants, hindered aminelight stabilizers (HALS), aryl amines, phosphorus based antioxidants,copper heat stabilizers, polyhydric alcohols, tripentaerythritol,dipentaerythritol, pentaerythritol and combinations thereof.
 11. Thethermoplastic composition of claim 1 wherein the polyamide resin isselected from a group consisting of Nylon 6, Nylon 6,6, Nylon 6,12,Nylon 4,6, Nylon 6,10, Nylon 7, Nylon 10, Nylon 10, 10, Nylon 12, Nylon12, 12, Nylon 6T, Nylon 6I, Nylon DT, Nylon DI, Nylon 6T/6I, Nylon6T/DT, Nylon 6/6,6, Nylon DT/DI, Nylon MXD-6 and blends and copolymersthereof.
 12. The thermoplastic composition of claim 1 wherein thesilicone based additive is evenly distributed throughout thethermoplastic composition.
 13. The thermoplastic composition of claim 1further comprising from about 0.1 to about 5.0 by weight of an olefinand maleic anhydride copolymer, wherein the an olefin and maleicanhydride copolymer has a molecular weight in the range of about 300 toabout 1,000,000 and the ratio of olefin to maleic anhydride is 1:1. 14.The thermoplastic composition of claim 13 wherein the olefin isethylene.
 15. The thermoplastic composition of claim 13 wherein theshear viscosity is greater than 1000 Pa when tested at a shear rate of100 sec-1.
 16. The thermoplastic composition of claim 13 wherein theshear viscosity is greater than 2000 Pa when tested at a shear rate of30 sec-1.
 17. The thermoplastic composition of claim 1 wherein thepolymer performance modifier is present in an amount from about 16% toabout 22% by weight and the silicone based additive is present in anamount from about 1.0% to about 5.0% by weight, wherein the impactstrength is at least 20 kJ/m2 when tested at −40° C.
 18. Thethermoplastic composition of claim 1 wherein the polymer performancemodifier is present at about 16% by weight and the silicone basedadditive is present in an amount from about 1.0% to about 5.0% byweight, wherein the impact strength is at least 70 kJ/m2 when tested atroom temperature.
 19. The thermoplastic composition of claim 1 whereinthe polymer performance modifier is present in an amount from about 18%to about 22% by weight and the silicone based additive is present in anamount from about 1.0% to about 5.0% by weight, wherein the impactstrength is at least 80 kJ/m2 when tested at room temperature.
 20. Thethermoplastic composition of claim 1 wherein the polymer performancemodifier is present at about 16% to about 22% by weight and the siliconebased additive is present in an amount from about 1.0% to about 5.0% byweight, wherein the tensile strength is at least 20 Mpa at 50%elongation when tested at 100% moisture saturation.
 21. Thethermoplastic composition of claim 1 wherein the polymer performancemodifier is present at about 16% to about 22% by weight and the siliconebased additive is present in an amount from about 1.0% to about 5.0% byweight, wherein no break was observed at 200% elongation when tested at100% moisture saturation.
 22. A molded article comprising thethermoplastic composition of claim
 1. 23. A process for forming thethermoplastic composition of claim 1 comprising the steps of adding apolymer performance modifier and a silicone based additive to apolyamide resin and mixing the polymer modifier, silicone based additiveand polyamide resin to form a high impact polymer.
 24. The process ofclaim 23 wherein the polymer performance modifier comprises an impactmodifier selected from the group consisting of a maleic anhydridefunctionalized elastomeric ethylene copolymer, a maleic anhydridefunctionalized ethylene, α-olefin copolymer, a terpolymer of ethylene,acrylic ester and maleic anhydride, a maleic anhydride grafted (MAH)polyolefin elastomer and combinations thereof.
 25. The process of claim23 wherein the polyamide resin is Nylon 6,6.